Aircraft Carrier with Force Z 1941

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Carl Schwamberger
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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 03 Oct 2023 17:11

T. A. Gardner wrote:
03 Oct 2023 15:50
LWD wrote:
02 Oct 2023 18:17
But there wasn't an escort with the Japanese bombers and if there had been they would have had to turn back before they found Force Z or ditched on the way home.
In the historical case, the Japanese bombers spent time trying to find the British ships before actually doing so. The exact location of the British fleet was not known to the bomber crews. A better 'what-if' here might be the bombers fail to find the British ships and they escape unscathed. What would come next?

Correct. it was the same when the air group hied off after the Lexington. The Zeros at Rabual lacked the range to the suspected location. In that case at least two, and possibly three reconnaissance aircraft had tracked and reported the USN TF location. They had a much better fix on it.

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Re: Aircraft Carrier with Force Z 1941

Post by T. A. Gardner » 03 Oct 2023 17:22

Carl Schwamberger wrote:
03 Oct 2023 17:11
T. A. Gardner wrote:
03 Oct 2023 15:50
LWD wrote:
02 Oct 2023 18:17
But there wasn't an escort with the Japanese bombers and if there had been they would have had to turn back before they found Force Z or ditched on the way home.
In the historical case, the Japanese bombers spent time trying to find the British ships before actually doing so. The exact location of the British fleet was not known to the bomber crews. A better 'what-if' here might be the bombers fail to find the British ships and they escape unscathed. What would come next?

Correct. it was the same when the air group hied off after the Lexington. The Zeros at Rabual lacked the range to the suspected location. In that case at least two, and possibly three reconnaissance aircraft had tracked and reported the USN TF location. They had a much better fix on it.
22nd Air Flotilla had 25 A6M2 (18 servicable) in French Indochina that could have reached Force Z, but the flight would have to be close to on the money without a search for them to do it. The A6M2 with external fuel tank could fly a bit over 1900 miles.

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 03 Oct 2023 17:53

T. A. Gardner wrote:
02 Oct 2023 18:06

Well, RN practice at the time was each ship for itself when it came to AA fire. So, the carrier was on its own. RN doctrine, at the time, also called for AA fire to be the primary defense of the ship along with maneuvering. The RN CAP would likely be something like 4 Fulmars up to take on the raid. So, you have what amounts to--sort of--four Fairey Battles up for fighters. That is, the Fulmars are like F2A Buffaloes dragging a couple of large sandbags trying to take on Zeros. What they aren't is tough little F4F's that are a match for the escort when it comes down to it. We know from the Fulmar's performance over Celyon that it was no match for a Zero.

The AA fire from a single ship isn't going to have anywhere the same impact as a battlegroup operating in a ring formation where every ship in range is firing on the attackers in support of the carrier. With Force Z you have three capital ships (2 x BB 1 CV) maneuvering independently to avoid attack. On of the BB's has pretty crappy AA capacity on top of that.

The escorting destroyers, such as they are, have for all intents zero AA capacity. Typically, they had something like a couple of quad .50 Vickers mounts or maybe 4 20mm and an antique, ancient, 3" HA gun with no fire controls. They were going to contribute nothing to the air defense.
The number of bomb hits on any of the RN ships of Force Z was exactly one. A 250 kg bomb hit a seaplane hanger & failed to penetrate the deck armor. If my information is correct the japanese bombers were attacking from about 10,000 get, as per their doctrine. This low hit rate by bombs was characteristic of the Japanese twin engined navy bombers. ie: multiple attacks on the US cruiser Houston resulted in exactly one hit. That was without a 'escort ring' or CAP. Like many other air forces the Japanese bombing tactics vs ships in 1942 were not very good. Where dive bombing techniques were impractical the doctrinal medium altitude techniques were 'poor'.

Against the Lexington they sent unescorted bombers, tho the reconnaissance planes did report a carrier in one message, and "carriers" in another. Against admiral Waters TF in January 1943 they again sent unescorted bombers, despite a intel evaluation there were carriers present. (half right, the escort carriers were sent away). Int hat case the bombers carried torpedos and were able to get some damaging hits, sinking the Chicago.

In the case of Force Z the Japanese attacked in relative small groups, averaging about nine planes. The Lexington fended off 17 divided in a well coordinated simultaneous attack in two groups.

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Re: Aircraft Carrier with Force Z 1941

Post by Tom from Cornwall » 03 Oct 2023 22:34

Of course, it might be that Phillips acted differently if he had a force that included an aircraft carrier.

Regards

Tom

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 09 Oct 2023 17:56

I agree. He'd have somewhat better reconnaissance. Even if he had not intercepted any of the transport groups its possible there would have been a fight between him & the covering cruiser force. That group was actually looking for Phillips.

Had a Japanese cruiser group intercepted Phillips it might have gone just as badly. The Japanese had their cruisers stuffed with torpedos. The Type 93 which was about the best anyone had. Phillips like everyone else had no clue about the power or range of this weapon, and knew nothing about how many such a surface group would carry may have been at high risk had he engaged the cruisers. It would come down to range. The Type 93 had good accuracy at a range up to 22,000 meters (with a speed setting of 48 knots ph, but at a speed setting of 34 it could also get hits out to 40,000 meters. Precisely how accurate at each range is not precisely clear but a hit rate in excess of 10% could be expected at the higher speed setting, and something between 4 & 7 % at the lower speed setting/range.

Those at a glance would seem unimpressive hit rates. What helped here is Japanese doctrine was the fill the sea with torpedos, and do it as soon as the enemy was sighted in range. In 1941 & 1942 Japanese surface commanders seldom dithered over the question of launching torpedos. During that period fifty torpedos would be a small attack, typically they put sixty to eighty in the water, & on one occasion slightly over 100. That was usually en mass and not in dribbles over the course of a battle.

Had Phillips been engaged by the Yura, Kinu and Kumano covering the transport groups and any destroyers he would have had a minimum of thirty torpedos from the cruisers, plus 8-10 each from any destroyers with them. This would have been a night engagement so any torpedos launched would have been at the nearer range. Perhaps as close as 5,000 to 8,000 meters. Even if only half the torpedos are launched due to damage from Phillips guns two torpedo hits can be expected at the near range. A full volley at long range would see up to 3-4 hits average.

If the larger 2d Fleet Force intercepts Phillips that would have the three Takao class cruisers and eight destroyers. Capable of a 60+ torpedo volley. Against the separate Cruiser Division 7 of four Mogami class a light cruiser, and four destroyers eighty+ torpedos may have been possible. Number of reloads varied, but all had some. Although the Japanese skippers seldom launched two torpedo attacks in the same battle a pair of battle ships would have been worth the expected losses to the cruiser/destroyer force.

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Re: Aircraft Carrier with Force Z 1941

Post by LWD » 09 Oct 2023 18:56

The range of the Type 93's was also a problem in their usage. Against a stationary target doubling the range cuts the p(h) in half against a moving one the effect is even greater. There's also the issue of the cruisers getting hit with the torpedoes and their oxygen refueling on board. Early in the war the Type 93's were somewhat temperamental from what I recall as well. I think I read that in some of the early battles almost half detonated prior to reaching their targets. This article goes into some detail on it:
http://www.navweaps.com/index_tech/tech-067.php

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Re: Aircraft Carrier with Force Z 1941

Post by Tom from Cornwall » 09 Oct 2023 21:50

Carl Schwamberger wrote:
09 Oct 2023 17:56
I agree. He'd have somewhat better reconnaissance. Even if he had not intercepted any of the transport groups its possible there would have been a fight between him & the covering cruiser force. That group was actually looking for Phillips.
Hi Carl,

Better reconnaissance but also a strike capability so his whole mind-set might have been different. Having an air group with, hopefully, an experienced commander might also have been useful during the discussions which Phillip held with other services on arrival in Singapore. And, of course, it might be that they didn’t get to Singapore before 7 December 1941.

Regards

Tom

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 10 Oct 2023 00:07


That parallels my analysis. Tho I only examined multiple target or ship actions. Those with one target ship, like the Exeter I did not use. I was trying to come to a group vs group average. Tho the Japanese hit rate in the samples was not what they hoped for in their doctrine the results were helpful. Particularly around Guadalcanal where they inflicted a lot of cumulative damage to the USN cruisers and destroyers. Halseys whiff of desperation in dispatching the Washingto & South Dakota to interdict the Japanese force off Guadalcanal is obscured in the narrative in that none of the torpedos hit the US BB. Had the averages played out 1-3 hits would have occurred on one or both of the US BB. Lee was lucky that night, as well as skilled.

One other conclusion I came to is the Japanese gunnery was not as destructive as the USN. Had the Japanese followed US or British doctrine and practice they might have had a severe problem. Stripping all the torpedo hits from the cruiser launched torpedos from the night battles around Guadalcanal leaves the Japanese in a far worse position. They needed some large changes in the gunnery & battle practice to achieve what they did with beaucoup torpedos.

I suspect that had they been less enamored with the Decisive Battle fantasy and used their cruiser/destroyer forces a bit differently in 1942 the IJN would have made life much worse for the USN in the S Pac

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 10 Oct 2023 00:16

Tom from Cornwall wrote:
09 Oct 2023 21:50
Better reconnaissance but also a strike capability so his whole mind-set might have been different. Having an air group with, hopefully, an experienced commander might also have been useful during the discussions which Phillip held with other services on arrival in Singapore. And, of course, it might be that they didn’t get to Singapore before 7 December 1941.
Its tough for me to guess what Phillips might have done. This was with experience fighting the German and Italians with carriers. How that would translate over to fighting the Japanese in December 1941 I'll not speculate at this point. Admiral Brown turned the Lexington TF around when he knew he'd been located. Which did not prevent a large coordinated massed strike. If the Japanese had carried torpedos vs bombs they'd have gotten at few in the water & on track to the Lexington as the battle played out. More if they had altered their tactics a little.

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Re: Aircraft Carrier with Force Z 1941

Post by LWD » 10 Oct 2023 17:55

Found some info on the reliability early war of the Type 93:
http://www.navweaps.com/Weapons/WTJAP_WWII.php
"...Many accounts of the 1942 battles describe these torpedoes prematurely detonating after running the arming distance or detonating once they crossed the target's wake. For example, it was estimated that about a third of the torpedoes launched at the Battle of the Java Sea (Sea Engagement off Surabaya) either prematured or detonated on wakes...."

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Re: Aircraft Carrier with Force Z 1941

Post by lordroel » 13 Oct 2023 15:17

Question, if the Germans still mange to have carriers in 1941 when the United States entered the war, would the United States deploy some fleet carrier to hunt them ore are escort/light carriers tofeghter with the Royal Navy enough.

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 13 Oct 2023 15:40

Japanese doctrine appears to have been based on the idea surface ship launched torpedo attacks would have a 25% or better hit rate. Thats from a post war analysis of the IJN Decisive Battle Doctrine. May be accurate, but I don't have much for collaboration. Its not clear if that was at the 22,000 yard range (12.5 statute miles, or at the horizon from a destroyer bridge/range finder), or at the longer range where you need some serious elevation for your range finder.

The reality was that in the typical night battle, at ranges under 15,000 yards, and in typical confusion the hit percentages were a lot closer to 10% or less. There are a few examples of 25% or higher hits, but the circumstances were not 'common'. This does not bode well for the Repulse and PoW if they encounter either of the Cruiser/Destroyer groups.

Four or five years ago we ran a hypothetical of the USN battle fleet of 1941 vs the IJN battle line. Neither side did much damage with gunnery as the IJN commander sent half his destroyers, backed by a some cruisers on a early torpedo attack. The game gave up a hit rate of 15% at launch ranges mostly under 10,000 yards. About half the US BB were sinking or holed before the gunnery battle really got rolling. The hit rate the game modeled may have been high, but we were short IJN destroyers and ran out of miniatures before we got half the probable number on the table. IIRC fifteen cruisers & destroyers executed the attack with approx five sunk or sinking as the attack was completed.

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 13 Oct 2023 15:53

lordroel wrote:
13 Oct 2023 15:17
Question, if the Germans still mange to have carriers in 1941 when the United States entered the war, would the United States deploy some fleet carrier to hunt them ore are escort/light carriers tofeghter with the Royal Navy enough.
The Ranger, Wasp, and Hornet were in the Atlantic in 1941. The Ranger lacked accommodation for torpedos and usually did not embark torpedo bombers. Considering the defects of the USN torpedos a bomber group entirely of SBD would have been a advantage. The Hornet and Wasp would have been launching torpedo bombers with largely dud torpedos. A look at the results of the USN air torpedo attacks against the Japanese in 1942 suggests they'd have not damaged any German ships.

The Hornet moved to the Pacific in Mach 1942 to stand in for the Saratoga which was under repair for a Japanese torpedo hit back in january. The Wasp was moved to the Pacific later in the summer after the Lexington & Yorktown were sunk. The Saratoga was turned to the Fleet at the end of May 42, and returned to dry dock in September after another successful submarine attack.

Given the small air group the German carriers were to embark a couple CVE could match them. But, the CVE were not fast. That makes them problematic in fleet vs fleet combat.

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Re: Aircraft Carrier with Force Z 1941

Post by EwenS » 13 Oct 2023 15:56

lordroel wrote:
13 Oct 2023 15:17
Question, if the Germans still mange to have carriers in 1941 when the United States entered the war, would the United States deploy some fleet carrier to hunt them ore are escort/light carriers tofeghter with the Royal Navy enough.
On 7 Dec 1941 the US Atlantic Fleet had the following carriers:-

CV-4 Ranger
CV-5 Yorktown (left for the Pacific 16 Dec 1941)
CV-7 Wasp (departed for the Pacific 6 June 1942 after spending April/May operating with British fleets)
CV-8 Hornet (worked up in the Atlantic until leaving for the Pacific 4 March 1942).
CVE-1 Long Island (Training Carrier until leaving for the Pacific 10 May 1942)


The first 3 were engaged on Neutrality patrols while they remained in the Atlantic so would have been available to hunt down enemy raiders of any variety. Problem however was that Ranger and Wasp only carried a handful of torpedo bombers (c4 IIRC)

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Re: Aircraft Carrier with Force Z 1941

Post by Carl Schwamberger » 13 Oct 2023 16:13

Im rechecking the Japanese record of USN torpedo bomber hits/detonations. From memory I can say it was awful in 1942. While the Shoho had at least one and probably more torpedos detonate against it that was from a large attack with increased odds of a trigger functioning correctly. Otherwise the USN torpedo bomber crew in 1942 may as well been attacking wit their pair of MG. I strongly suspect the USN carriers would have been damaging the German ships with dive bombers or not at all.

After the trigger and guidance problems were solved during 1943 the US torpedos were reasonably effective, but not in 1941-42

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